A parking brake system in a vehicle is described in DE 10 2004 004 992 A1 in which a clamping force holding the vehicle at a standstill is produced by means of an electric brake motor by the electric brake motor displacing a brake piston against a brake disk. The parking brake system is integrated within the hydraulic vehicle brakes. In the normal braking mode, the brake piston is pressed against the brake disk by the hydraulic brake fluid.